1. Field of the Invention
This invention relates to construction modules, specifically to releasably connectable modules that exhibit the construction properties of polyhedra and can be easily injection molded as single pieces of plastic.
2. Prior Art
“Box Shaped” Construction Modules
Many space-filling cube and brick-shaped polyhedral modules are known in the prior art. The major advantage of these modules is that they can be molded as one piece of plastic and are, therefore, economical to manufacture. However, these brick-type construction blocks are typically severely limited in terms of which of their six faces can mate with one of the six faces of another, identical, block. Four of their “side” walls are usually sheer, while their top and bottom surfaces incorporate either studs or recesses (as shown in Christiansen's U.S. Pat. No. 3,005,282—Oct. 24, 1961). In most cases, out of six possible faces of such a brick, there is only one other compatible brick face that can mate with any given mating surface.
Having a limited number of compatible mating surfaces on each module is disadvantageous for at least two reasons. First, it complicates construction; the “next block” cannot simply be added on in any direction. Second, it limits accessories that might be added to a structure. For example, if one wanted to attach a snap-on eye, arm, or nose, there are a very limited number of available surfaces for such attachments.
There are examples of one-piece brick-type construction modules that are improved in terms of their connecting versatility. In U.S. Pat. No. 6,648,715 (Nov. 18, 2003), Wiens, et al. describe bricks with two single-sex faces that can be mated to one another and four hermaphroditic faces that can be mated to one another. These bricks can be manufactured with relative ease, and they allow any face of a block to mate with at least one other face of an identical block, but they do not allow any face of a block to mate with any other face of an identical block. Tops can be mated to bottoms, and sides can be mated to sides; but tops cannot be mated to tops, sides cannot be mated to tops, sides cannot be mated to bottoms, and bottoms cannot be mated to bottoms.
In addition to the problems already mentioned, all cube and brick modules have at least two more detractions. First, none of these modules are particularly attractive. These known cube and brick modules, which incorporate at least three distinct types of faces, lack the aesthetic appeal of symmetry. They achieve limited functionality, but they are not beautiful structures in and of themselves. The second detraction of cube and brick blocks is that their space-filling orientations are rather mundane and uninteresting. Their possible building directions are up, down, left, and right. These blocks cannot connect at more novel angles, such as 45 degrees upward and to the right.
“Facially-Symmetric” Construction Modules
Construction modules with symmetric faces are also known in the prior art. Several U.S. Patents (U.S. Pat. Nos. 5,098,328, by Bierens—Mar. 24, 1992; 6,439,571, by Wilson—Aug. 27, 2002; and D359,315, by Tacey—Jun. 13, 1995) describe cube blocks with “six face symmetry.” All of these blocks' faces are identical, which allows any face on one of these blocks to connect with any face on another identical block.
These blocks represent improvements over the aforementioned cubes and bricks, in that their connectability is more versatile. Their symmetry also renders them more aesthetically appealing. However, the overarching problem with these prior art “facially symmetric” building blocks is that none of their designs can be easily manufactured as one piece of plastic, using straight-pull injection molding processes. For example, Beerens' patent suggests a method by which his cubes might be manufactured as six separate pieces, which must then be assembled before use.
Hollister describes a somewhat similar plan for a tetrahedron building block with symmetrical faces in his U.S. Pat. No. 6,152,797 (Nov. 28, 2000). Hollister's patent showed how his tetrahedron block might be manufactured as four separate triangular faces and four separate insertable connectors—eight pieces in all. In addition to the cost involved, this required assembly is troubling because it limits the materials that can be used to create these modules; some resins are not easily joined. Furthermore, there is always a danger of these complex modules coming apart, creating safety hazards.
Non-Box Shaped Construction Modules
Most prior art construction modules are box-shaped. Construction modules with other polyhedral geometries have represented a significant challenge to inventors. The advantage of these non-box-shaped building blocks is that they are not limited to vertical and lateral connections. Their faces do not necessarily lie parallel or perpendicular to one another. However, the same interesting geometry that has made them enticing candidates for building blocks has also rendered them impossible to manufacture economically. They have proven especially difficult to manufacture as one piece of material. Hollister's tetrahedron, mentioned in the previous paragraph, provides one example of this difficulty. In U.S. Pat. No. 7,247,075 (Jul. 24, 2007) Von Oech describes a golden right rhombic pyramidal polyhedron that can be manufactured as two pieces of material, plus multiple magnets. In U.S. Pat. No. 5,501,626 (Mar. 26, 1996), Harvey describes polygonal pieces that may be snapped together at their edges to create polyhedra.
Lalvani (U.S. Pat. No. 4,723,382) discloses an icosahedral system of ten polygonal members that may be assembled to create polyhedra as well as planar shapes. Lalvani's basic polygon members may be solid or “open lattice[s].” While Lalvani does disclose a means of connecting multiple panels or lattices to create polyhedra, he does not offer an easily manufactured integral polyhedron. In addition to the art of Lalvani and the others mentioned above, many other such polyhedra, which are constructed from individual, snap-together faces, are known.
Many other polyhedron inventors do not even address the issue of manufacturing. Evans (U.S. Pat. No. 6,257,574) discloses a variety of multi-polyhedral puzzles, where polyhedral blocks abut to form larger structures. Evans shows many configurations and enumerates many geometric specificities of polyhedral blocks, but he does not focus on how those blocks are made.
Viewed collectively, the prior art in construction modules suggests a clear failure to create construction modules with all of the following properties: one-piece, straight-pull, injection moldability; overall aesthetic appeal; compatible connectivity in a variety of directions; and a wide variety of possible polyhedral embodiments.
3. Objects and Advantages
Accordingly, it is the object of my invention to provide a variety of novel construction modules, each with a broad combination of advantages unknown in the prior art.
A first object of my invention is to provide some identical construction modules that can form aligned, face-to-face connections where one planar surface “matches up” and abuts with a compatible surface.
A second object of my invention is to provide some sets of construction modules that are space-filling. In other words, these sets of construction modules can tessellate, fully occupying the cells of a geometric honeycomb.
A third object of my invention is to provide construction modules that can be manufactured as a single piece of material, by a straight-pull injection mold. Such modules have reduced tooling costs, require no assembly, and cannot come unassembled. One-piece modules may also be manufactured in a variety of materials, some of which may pose and assembly problems to a multiple part module.
A fourth object of my invention is to provide some construction modules with unique geometries that transcend the common box shape.
A fifth object of my invention is to provide construction modules that are easily scalable, so that they may satisfy a variety of uses and age groups. A change of scale can also address a number of other manufacturing concerns, such as loose machining tolerances.
A sixth object of my invention is to provide individual modules with interesting symmetries. In a set of my modules, each individual module in a set has interesting symmetry, all by itself. Each can stand alone as a geometric work of art. Furthermore, when my individual modules are mated together, fascinating and continuous symmetry patterns emerge across multiple modules.
A seventh object of my invention is to provide connectively compatible construction modules of differing geometries. For example, some of my embodiments having surfaces coplanar with cubooctahedral, truncated octahedral, and truncated tetrahedral template can be made to fit together in a 3-D tessellation. Connective compatibility also allows variety of modules to be used together as a construction system. In this way, an animal sculpture could have a body made from isosceles tetrahedra and four legs constructed from sets of cubes.
A final object of my invention is to provide construction modules that can be made releasably connectable. All of my embodiments are designed in such a way that snap-fit connectors may be incorporated into their surfaces. The obvious advantage conferred by such connectability is that complex and semi-permanent structures can be built.
Further objects and advantages of my invention will become apparent from a consideration of the drawings and ensuing descriptions.